This application requests funds to obtain electronic instrumentation to update existing ultrasonic exposure facility instruments. The original existing electronic instruments were designed and fabricated approximately 200 years ago and are now in need of major refurbishing in order to assure that accurate and reliable usage continues. The instrumentation is essential for the exposure of animal systems to study mechanisms of interaction, immunological response, dosimetry, and for the purposes of measuring ultrasonic propagation properties of biological media. The proposed updating will further make avaiable the capability of greatly expanding the scope of the work, undertaken by the investigators dealing with different ultrasonic topics, by allowing for short pulse irradiations to be carried out, and thereby opening the research armamentaria to the temporal domain of clinical diagnostic ultrasound while providing for the substantial wave amplitudes needed for interactive studies.